This invention relates to decorative panel assemblies for vehicles such as automobiles and trucks, boats, and aircraft, as well as for appliances, wherein the panel assembly includes indicia, insignia or designs which are illuminated for display purposes.
In recent years, varying efforts have been made to provide illuminated decorative displays especially for use in vehicles including automobiles, trucks, boats and aircraft, as well as in other applications such as appliance doors, store displays, and the like. Such displays have included various arrangements such as mirror plates having illuminated indicia or designs therebehind, edge lighted transparent sheets with letters or other indicia etched or carved into the surfaces for illumination, and numerous types of illuminated instrument panel displays using electroluminescent layers of one type or another. Electroluminescent panels typically include a layer of electroluminescent phosphor or phosphor mixed with some type of dielectric material sandwiched between electrically conductive coatings or layers which are connected to appropriate power sources. This entire assembly is usually applied in stages to a transparent or other supporting substrate and illuminated by the connection of an appropriate power source to the conducting layers such that light is emitted through or away from the substrate. In some cases, one of the electrically conductive layers is configured in the desired design such that the electroluminescent layer provides light only in the areas of the configured electrode.
More recently, efforts have been made to apply electroluminesent technology to the display of automobile insignia and other designs in passenger cars and other vehicles. At least one prior art assembly has included a solid metal symbol or insignia of a predetermined design behind which was placed a relatively planar electroluminescent assembly or pad of a large thickness. Wire leads were connected directly to the electroluminescent pad. This assembly suffered from several drawbacks however.
First, it was difficult to secure to the exterior of the vehicle and yet protect it from the elements to which an automobile is exposed in normal use. Moreover, the power supply required by the assembly created significant radio interference within the automobile and, thus, of necessity, was required to be placed at as great a distance from the radio as possible to reduce such interference as much as possible. Of course, this severely limited the positions in which the insignia could be displayed on the vehicle.
Further, prior known electroluminescent pad assemblies were of significant thickness, i.e., in the range of 0.060 to 0.090 inches. Such thickness required special mounting arrangements for the assemblies and virtually eliminated any possibility of laminating the electroluminescent assemblies within panel displays such as window assemblies or other areas where positioning and attachment to vehicles would be made easier.
In addition to the above problems, the required electrical connections to prior known assemblies were typically bulky or obtrusive and prevented many aesthetically pleasing displays of the type desired for vehicle applications. Electrical connections typically included highly visible solid metallic conductors leading to light sources or electroluminescent pad assemblies. Of necessity, such conductors usually had to be led directly to the back or sides of a display and required significant masking to make the entire assembly visually pleasing. Accordingly, indicia or design displays could not be positioned in the center of large transparent areas or in the middle of other panel displays without unsightly conductors being included which would detract from the appearance of the assembly.
Therefore, the need was apparent for a lighted indicia, insignia or design display assembly which would be sufficiently small to enable incorporation in laminated panel assemblies for vehicles such as laminated windows or the like, and yet which would eliminate unsightly electrical conductors which previously had prevented use of illuminated displays in many applications. The present invention was devised as a solution to these and other problems.